This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. The goal of this work is to determine the crystal structures of key complexes of vesicle coat proteins bound to cargo transport signals, ARF-family GTPases and SNARE proteins. We are focusing primarily on the COPII coat complex that participates in ER-to-Golgi vesicular trafficking, and the COPI coat that functions in vesicle budding from the Golgi apparatus.